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Guanine Quadruplex DNA Regulates Gamma Radiation Response of Genome Functions in the Radioresistant Bacterium Deinococcus radiodurans.
Mishra, Shruti; Chaudhary, Reema; Singh, Sudhir; Kota, Swathi; Misra, Hari S.
Afiliação
  • Mishra S; Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.
  • Chaudhary R; Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.
  • Singh S; Life Sciences, Homi Bhabha National Institute, Mumbai, India.
  • Kota S; Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India.
  • Misra HS; Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India swatik@barc.gov.in hsmisra@barc.gov.in.
J Bacteriol ; 201(17)2019 09 01.
Article em En | MEDLINE | ID: mdl-31235513
Guanine quadruplex (G4) DNA/RNA are secondary structures that regulate the various cellular processes in both eukaryotes and bacteria. Deinococcus radiodurans, a Gram-positive bacterium known for its extraordinary radioresistance, shows a genomewide occurrence of putative G4 DNA-forming motifs in its GC-rich genome. N-Methyl mesoporphyrin (NMM), a G4 DNA structure-stabilizing drug, did not affect bacterial growth under normal conditions but inhibited the postirradiation recovery of gamma-irradiated cells. Transcriptome sequencing analysis of cells treated with both radiation and NMM showed repression of gamma radiation-responsive gene expression, which was observed in the absence of NMM. Notably, this effect of NMM on the expression of housekeeping genes involved in other cellular processes was not observed. Stabilization of G4 DNA structures mapped at the upstream of recA and in the encoding region of DR_2199 had negatively affected promoter activity in vivo, DNA synthesis in vitro and protein translation in Escherichia coli host. These results suggested that G4 DNA plays an important role in DNA damage response and in the regulation of expression of the DNA repair proteins required for radioresistance in D. radioduransIMPORTANCEDeinococcus radiodurans can recover from extensive DNA damage caused by many genotoxic agents. It lacks LexA/RecA-mediated canonical SOS response. Therefore, the molecular mechanisms underlying the regulation of DNA damage response would be worth investigating in this bacterium. D. radiodurans genome is GC-rich and contains numerous islands of putative guanine quadruplex (G4) DNA structure-forming motifs. Here, we showed that in vivo stabilization of G4 DNA structures can impair DNA damage response processes in D. radiodurans Essential cellular processes such as transcription, DNA synthesis, and protein translation, which are also an integral part of the double-strand DNA break repair pathway, are affected by the arrest of G4 DNA structure dynamics. Thus, the role of DNA secondary structures in DNA damage response and radioresistance is demonstrated.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: DNA / Regulação Bacteriana da Expressão Gênica / Genoma Bacteriano / Deinococcus / Quadruplex G / Raios gama Idioma: En Revista: J Bacteriol Ano de publicação: 2019 Tipo de documento: Article País de afiliação: Índia

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: DNA / Regulação Bacteriana da Expressão Gênica / Genoma Bacteriano / Deinococcus / Quadruplex G / Raios gama Idioma: En Revista: J Bacteriol Ano de publicação: 2019 Tipo de documento: Article País de afiliação: Índia